Inclusion Criteria:
1. The participant provides written informed consent using an Informed Consent Form (ICF) that is reviewed and approved by the Institutional Review Board (IRB) or an acceptable patient surrogate.
2. The participant is ≥ 18 years old and less than 85 years old.
3. Patients with symptomatic large vessel occlusion (LVO) who undergo MT as part of their standard of care and have residual occlusion involving the anterior, middle or posterior cerebral arteries resulting in a eTICI score greater than 2b50 at the end of the procedure with three or less MT device passes.
4. Estimated delay to onset of rescue Pulse NanoMED MicroBead administration \<9 hours from symptom onset, defined as the point in time the patient was last known well (LKW).
5. Post-MT and has had thrombolytic therapy \<9 hours prior to the proposed start time of System therapy
6. No significant pre-stroke functional disability (modified Rankin scale 0-1)
7. Baseline NIHSS≥6
8. ASPECTS \>6 on non-contrast CT (NCCT) scan if symptoms lasting \<8 hours
9. CT-Perfusion (CTP) is optional, if performed, should demonstrate rCBF \<30% lesion volume ≤70 mL.
10. Imaging should be obtained within 75 minutes of the onset of mechanical thrombectomy.
Exclusion Criteria:
1. NIHSS score on admission \>25
2. Use of carotid artery stents during the endovascular procedure requiring dual antiplatelet therapy
3. Female who is pregnant or lactating or has a positive pregnancy test at the time of admission
4. Current participation in another investigational drug or device treatment study
5. Known allergy or sensitivity to iron
6. Known hereditary or acquired hemorrhagic diathesis, coagulation factor deficiency
7. Known coagulopathy, INR \>1.7, or use of novel anticoagulants \<12h from symptom onset
8. Known Platelets \<100,000
9. Known Renal Failure as defined by a serum creatinine \>3.0 mg/dl (or 265.2 μmol/l) or glomerular Filtration Rate \[GFR\] \<30
10. Subject who requires hemodialysis or peritoneal dialysis or who has a contraindication to angiogram for whatever reason
11. Any hemorrhage on CT/MRI
12. Clinical presentation suggests a subarachnoid hemorrhage, even if initial CT or MRI scan is normal.
13. Suspicion of aortic dissection
14. Subject currently uses or has a recent history of illicit drug(s) or abuses alcohol.
15. History of life-threatening allergy (more than rash) to contrast medium
16. SBP \>185mmHg or DBP \>110mmHg refractory to treatment
17. Serious, advanced, terminal illness with anticipated life expectancy \<6 months
18. Pre-existing neurological or psychiatric disease that would confound evaluation
19. Presumed vasculitis or septic embolization
20. Known sensitivity or allergy to contrast materials that cannot be previously treated properly
21. The subject takes Coumadin and its interruption could compromise their safety
22. Known allergy or contraindication to double antiplatelet treatment
23. Known hypersensitivity or contraindication to iron or polyethylene glycol-based agents
24. Known contraindication to MRI (examples include, but are not known, implantable cardioverter-defibrillator, pacemaker, clip-on or spiral aneurysm, neurostimulator)
25. The physical geometry of the subject that prevents the placement of the magnet
26. The subject has signs or symptoms of systemic infection/sepsis (temperature of ≥38.0 Celsius and/or white blood cell count of ≥12,000 cells/uL). If the subject has a localized infection, such as cellulitis or osteomyelitis, or the infection is properly treated and controlled, according to the discretion of the researcher, the patient can enroll
27. Known or suspected cardiovascular condition that causes a secondary or tertiary heart block, tachycardia-bradycardia syndrome, or symptomatic postural hypotension requiring medical intervention
28. Known or suspected symptomatic hemochromatosis or hemosiderosis
29. Known or suspected liver disease, such as hepatitis and/or cirrhosis
30. The subject has received iron replacement therapy or contrast for iron-based MRI in the previous 30 days
